POISONOUS PLANTS

Plant Identification

The old saying “Leaves of three, Let it be!” is a helpful reminder for identifying poison ivy and oak, but not poison sumac which usually has clusters of 7-13 leaves. Even poison ivy and poison oak may have more than three leaves and their form may vary greatly depending upon the exact species encountered, the local environment, and the season. Being able to identify local varieties of these poisonous plants throughout the seasons and differentiating them from common nonpoisonous look-a-likes are the major keys to avoiding exposure.

Poison Ivy

Poison Ivy leaves

Photos courtesy of U.S. Department of Agriculture

  • Eastern poison ivy is typically a hairy, ropelike vine with three shiny green (or red in the fall) leaves budding from one small stem
  • Western poison ivy is typically a low shrub with three leaves that does not form a climbing vine
  • May have yellow or green flowers and white to green-yellow or amber berries

Poison Oak

Poison Oak leaves

Photos courtesy of U.S. Department of Agriculture

  • Typically a shrub with leaves of three, similar to poison ivy
  • Pacific poison oak may be vine-like
  • May have yellow or green flowers and clusters of green-yellow or white berries

Poison Sumac

poison Sumac leaves

Photos courtesy of U.S. Department of Agriculture

  • Woody shrub that has stems that contain 7-13 leaves arranged in pairs
  • May have glossy, pale yellow, or cream-colored berries
Page last reviewed: June 1, 2018